Humber keel
The Humber keel was a type of single-masted, square-rigged sailing craft used for inshore and inland cargo transport around Hull and the Humber Estuary, in the United Kingdom, particularly through the late 19th and early 20th centuries. == History == The square sail arrangement of the Humber keel is most probably a descendant of the Saxon ship of the fifth century AD. The term "keel" is derived from the Anglo-Saxon word "ceol", which referred to a ship built using a longitudinal strengthening beam (keel) together with a single mast and square rigging.